The majority of Greenspan’s book details how gullibility plays out in various spheres of life. He begins by looking at gullible characters in literature and proceeds to offer real world examples of it in religion, war and politics, criminal justice, science and academia, finance and relationships, and vulnerable populations. The stories he relates in these sections—from apocalyptic cult followers to coerced false confessions to art world scams to the Iraq war—are a fascinating and disturbing chronicle of how deception and trust interact and the numerous ways human decision making processes can go terribly awry.

Greenspan raises a number of interesting questions throughout the course of this discussion, including how to find the balance between healthy skepticism and closed-minded cynicism. He also addresses such thorny issues as an individual’s right to personal autonomy vs. the responsibilities of others to protect vulnerable populations from exploitation. His comments on these issues with regards to early stage Alzheimer’s patients were particularly thought-provoking.

Though many people associate gullibility with low intelligence, the copious examples he gives of very smart people being duped show that tendencies towards gullibility are affected by far more than just intellectual capacity. Greenspan has outlined four elements that can influence whether or not a person will behave in a gullible fashion—the social situation, cognitive processes, type of personality, and physical/emotional state. In the final chapter, he offers some suggestions on how to become less gullible, including practical tips such as avoiding impulsive choices and learning how to disengage from coercive situations. As his own recent investment loss shows, however, sometimes the only way to become less gullible is to learn from past experience.

A lot of the information covered here was familiar to me from other reading I’ve done in the last few years, but this book is by far the most comprehensive collection of all of the things one needs to know to effectively evaluate the ideas we are exposed to about the world around us and how it works. It covers everything from the basics of possibility and logic, what makes an argument good or bad, different ways of knowing and perceiving, cognitive biases that can skew our objectivity and the foundations of scientific thought processes. Interspersed within the more technical portions of the text are sidebars applying the principles at hand to various popular extraordinary claims such as instances of apparent ESP and things like the Amityville haunting.

This book is an actual textbook. Though the authors do a fairly good job of making it readable by using these sidebars and other interesting examples for much of what they cover, there are still a few sections that were rather on the dry side. Though this made parts of the book a bit of a slog, what I learned from it was more than valuable enough for me to keep going.

Among the sections that I personally found most useful were the discussions of how quirks in our perceptual systems can cause us to misinterpret what’s happening around us, the problems with appealing to mystical experience as a way of knowing, and the discussion of just how damaging it can be to believe things on insufficient evidence. In a chapter called “Case Studies in the Extraordinary,” the critical thinking processes outlined earlier are applied to the juicy topics of homeopathy, dowsing, UFO abductions, communicating with the dead, near-death experiences, ghosts and conspiracy theories. The authors are careful to refrain from saying definitively whether these things are or aren’t real, but instead show the reader how to evaluate the evidence and come to their own conclusions about which ideas are genuinely worthy of consideration. Highly recommended for anyone who thinks.

Prior to reading this book, I had no idea that the origin of human nature was such a contentious topic amongst modern intellectuals. Seems that a lot of people think acknowledging that something like violence might have been evolutionarily adaptive is the same thing as condoning violence and excusing those who engage in it, or that admitting that men and women are genetically different justifies discrimination against women. Pinker spends a lot of time in this book carefully addressing these concerns while at the same time making a compelling argument that the current tendency to deny any genetic influence on society’s more vexing ills only handicaps our ability to successfully deal with our most serious problems.

Pinker is not shy about tackling controversial topics as he makes his points. The chapter in which he pointed to evidence showing that a child’s intelligence and personality are shaped far more by genes, peers and random influences than they are by parents got him an enormous amount of mail, as did the section in which he discussed genetic influences on our appreciation of the arts.

Despite the radical nature of many of the theories Pinker presents, I found myself having continuous “ah-ha!” moments as I read this book. At its core, the idea that we are shaped by our genes as well as our experiences fits far better with reality than the idea that we are all moldable blank slates. Though these theories may not intellectually fashionable, Pinker makes it clear that there are a wealth of benefits to be gained by accepting what science has to tell us about the true origins of human nature.

McGraw’s book is divided into three main sections. In the first, the author provides a wide-angle overview of the concept of soul. He traces the history of the soul from its origins in animism/shamanism through ancient Greece and into Christianity. I have little background in religious history, so this section gave me a much better understanding of the origins and development of the kind of dualistic thinking required to sustain belief in the idea of a soul.

In the second section, McGraw uses findings from modern neuroscience to chip away at the belief that a soul can exist separate from the physical matter of the brain. An extensive section on brain mechanics and a discussion of how diseases such as Alzheimer’s can rob a person of any familiar sense of self serves to effectively undermine the idea that there is a separate soul which remains immune to the onslaughts of the physical plane.

McGraw spends a lot of time in this section detailing the effects of numerous hallucinogenic drugs on the brain. His discussion of the use of psychotropic plants in religion was particularly fascinating to me. I had no idea that there are those who believe the origins of Hinduism grew from the roots of a rare psychedelic mushroom (though, now that I think about it, that does seem to make an awful lot of sense.) His survey of psychotropic plant use from shamanism to Delphi makes clear that hallucinogens have played a major part in the development of human religious ideas.

What I found most effective about this section was that it speaks directly to what other critics of religion have referred to as “the argument for personal experience.” Since I participated in a tradition where transcendent moments of euphoria and bliss were cited as proof of the existence of a spiritual plane, reading a deconstruction of how these states are created in the brain was particularly enlightening. McGraw makes an effective argument that—as powerful as these states may be—they can be entirely explained by our own neurochemistry and cannot be reliably used to argue for the existence of alternate dimensions outside of our own heads.

In the third section of the book, McGraw discusses the issues that need to be faced in the process of moving away from false but comforting ideas of religion towards a more mature understanding of the world and our very limited place in it. McGraw excels here in his discussion of the cognitive biases that make this process difficult; in contrast to others who condescend to religious adherents as simply stupid, McGraw carefully explains how genuinely difficult our brains have made it to change long-held beliefs. His discussion of studies done on how doomsday cults react to the repeated failure of doomsday to arrive will be particularly interesting to students of cultic issues.

Though I disagree with his heavy reliance on the ideas of Freud to explain why we are so prone to believing in an all-powerful god, I think McGraw is correct that no real progress can be made until human beings are willing to let go of the self-important idea that we will live forever and face the reality of our own imminent death. As unpalatable as this idea may be for some, McGraw is kind enough not to leave the reader empty-handed. A brief discussion of the philosophies taught by Buddha, Epicurus and the Stoics provides several alternative ways of relating to the challenges of life that do not require the fierce denial of our material reality.